Donald Trump may be the president-elect, but millennials remain skeptical that the real estate mogul will follow through on his big-ticket campaign promises.

According to an Economist/YouGov poll released this week, adults under 30 are least likely to believe that Trump will deliver on his “big, beautiful” border wall, release his sought after tax returns or appoint a special prosecutor to investigate Hillary Clinton’s private email server.

It’s true millennials voted overwhelmingly for Clinton, so it follows that those same voters might remain dubious of Trump’s more outlandish policy proposals. But Geoffrey Klapisch, a marketing consultant and professor at Emerson College, said millennial skepticism is more a product of Vermont Sen. Bernie Sanders’ loss in the Democratic primaries than Clinton’s general election flameout.

“Millennials are wired to be skeptical, that’s who they are,” Klapisch said. “With Bernie falling by the wayside, they went into the general election already jaded.”

Klapisch also credits Trump’s “unusual” candidacy and platform with turning off younger voters to the entire political process.

Trump’s proposed wall along the Southern border was his campaign’s jumping-off point, setting the tone for the entire race and putting immigration issues front and center for the entirety of 2016.

Nearly 75 percent of millennials polled were either unsure or unconvinced that Trump will succeed in building a wall that Mexico will pay for, but in the days following the election, Trump reiterated his commitment to the project, conceding that he would accept a fence only in “certain areas.”

Adults across the board expressed their cynicism in similar numbers when asked if they believe Trump will eventually release his tax returns.

Throughout the campaign Trump assured voters he would release his returns when he is through being audited by the IRS, despite the fact that an IRS audit doesn’t prohibit public disclosure.

Every major party presidential candidate since Richard Nixon has released their returns prior to the general election.

Young people were more split over Trump’s promise to further investigate, and jail, his political opponent. Many Republicans and Trump allies portrayed Clinton as a criminal throughout the campaign, though she was twice cleared by the FBI of any illegal activity.

“Lock her up” was one of the most common chants overheard at Trump events and became somewhat of a rallying cry for the president-elect’s most ardent supporters. The slogan could be seen on buttons and shirts at the Republican National Convention in Cleveland, but it seems Americans, at large, don’t know how seriously to take this particular promise.

More than this initial skepticism, Klapisch and others wonder how younger adults will respond to the Trump administration’s first year in office.

If millennials go into elections thinking it’s a poisoned or rigged process, Klapisch said, what’s to keep them engaged in the future?

Other things of note from the poll:

Trump’s promise to repeal the 2010 health care law upon entering office was his most believable pledge, followed by his promise to start deporting millions of undocumented immigrants.

Most adults express the greatest uncertainty when asked whether Trump is likely to follow through on his promises to renegotiate international trade agreements such as NAFTA and the Trans-Pacific Partnership.

But 61 percent and 58 percent of the 65-or-over age group expect Trump to rip up or reconfigure NAFTA and the TPP, respectively, breaking with other groups by a large margin.